Mammals

1. 1 By: Vivek Shukla & Ritesh Gupta Sub Teacher : Mrs. Sachi Sachan 1/2/2014

2. Seminar on Phylum Vertebrata By : Vivek Shukla and Ritesh 2 1/2/2014

3. Subphylum 2. Gnathostomata 3 CLASS 6. MAMMALIA By : Vivek Shukla and Ritesh 1/2/2014

4. Classification of Vertebrata 4 By : Vivek Shukla and Ritesh 1/2/2014

5. By : Vivek Shukla and Ritesh 5 1/2/2014

6. Salient Feature 6 By : Vivek Shukla and Ritesh 1/2/2014

7. General Characters 7  They are warm blooded and most evolved animals of Animal      Kingdom. Skin is provided with Hairs, Sweat glands & Sebaceous glands. The forelimbs and hind limbs are variously adapted for walking, running, climbing, burrowing, swimming or flying. Wings are absent (except in bats). The teeth are present within the socket of jaws (thecodont dentition) & are differentiated into incisors, canines, premolars and molars (heterodont). They have bone marrow. By : Vivek Shukla and Ritesh 1/2/2014

9.  Respiration is through lungs only.  The heart is four - chambered with two auricles and two     ventricles, They are viviparous forms of life, i.e., the young ones are born directly (except platypus & echidna) (& some give birth to very poorly developed young ones like kangaroo). A muscular diaphragm is present that separates thoracic cavity from the abdominal cavity. The females are provided with milk producing mammary glands that secrete milk for the nourishment of the young. In males, they become vestigeal. Body is divisible into head, neck, trunk and tail. By : Vivek Shukla and Ritesh 9 1/2/2014

13.  The     red blood corpuscles are non- nucleated biconcave (except in camel). External ear (pinnae) present. Middle ear with three ossicles (malleus, incus and stapes). The developing embryo gets the nutrition and oxygen through the placenta. Excrete urea (ureotelic animals). They live in all kind of habitats from equator to poles. They are primarily terrestrial animals. By : Vivek Shukla and Ritesh 13 1/2/2014

16. Urinary bladder – need more water per day. Advanced kidneys – filter more blood. By : Vivek Shukla and Ritesh 16 1/2/2014

17. Phylogeny 17 • Separated into three groups • Prototheria (before gestation) – egg laying mammals • Metatheria (middle gestation) – pouched mammals • Eutheria (true gestation) – live birth from uterus Phylogeny – Evolutionary history of organisms Gestation – the time period between fertillisation and parturition (delivery ). By : Vivek Shukla and Ritesh 1/2/2014

18. Milk 18 Produced in mammary glands  May have been sweat glands  Feed young, increase success By : Vivek Shukla and Ritesh 1/2/2014

19. Types of teeth  Incisors – cutting  Canines – can be enlarged, piercing  Carnassal – shearing, remove meat from bones  Molars - grinding 1/2/2014 By : Vivek Shukla and Ritesh 19

20. Cardiovascular System 20  Body temperature is internally regulated (endothermic)  Heart is 4-chambered  High metabolism  Heart rate – depends on size of animal (smaller = faster rate) By : Vivek Shukla and Ritesh

21. Reproductive System 21 Dioecious (unisexual)  Highly variable in shape.  Placental mammals.  Nonplacental mammals. By : Vivek Shukla and Ritesh 1/2/2014

22. Reproductive System 22  Most mammals are viviparous, giving birth to live young. However, the five species of monotreme, the platypuses and the echidnas, lay eggs. The monotremes have a sex determination system different from that of most other mammals. In particular, the sex chromosomes of a platypus are more like those of a chicken than those of a therian mammal. By : Vivek Shukla and Ritesh 1/2/2014

23. Digestive System 23 Length differs based on diet  Predators short  Herbivores very long  Omnivores medium length By : Vivek Shukla and Ritesh 1/2/2014

24. Skeletal system 24  The majority of mammals have seven cervical vertebrae (bones in the neck), including bats, giraffes, whales, and humans. The exceptions are the manatee and the two-toed sloth, which have only six cervical vertebrae, and the threetoed sloth with nine cervical vertebrae. By : Vivek Shukla and Ritesh 1/2/2014

25. Nervous System 25  All mammalian brains possess a neocortex, a brain region unique to mammals. Placental mammals have a corpus callosum, unlike monotremes and marsupials. The size and number of cortical areas (Brodmann's areas) is least in monotremes (about 810) and most in placentals (up to 50). By : Vivek Shukla and Ritesh 1/2/2014

26. Feeding 26  To maintain a high constant body temperature is energy expensive – mammals therefore need a nutritious and plentiful diet. While the earliest mammals were probably predators, different species have since adapted to meet their dietary requirements in a variety of ways. Some eat other animals – this is a carnivorous diet (and includes insectivorous diets). Other mammals, called herbivores, eat plants. A herbivorous diet includes subtypes such as fruit-eating and grass-eating. An omnivore eats both prey and plants. Carnivorous mammals have a simple digestive tract, because the proteins, lipids, and minerals found in meat require little in the way of specialized digestion. Plants, on the other hand, contain complex carbohydrates, such as cellulose. By : Vivek Shukla and Ritesh 1/2/2014

27. 27  The digestive tract of an herbivore is therefore host to bacteria that ferment these substances, and make them available for digestion. The bacteria are either housed in the multichambered stomach or in a large cecum. The size of an animal is also a factor in determining diet type. Since small mammals have a high ratio of heat-losing surface area to heatgenerating volume, they tend to have high energy requirements and a high metabolic rate. By : Vivek Shukla and Ritesh 1/2/2014

28. 28  Mammals that weigh less than about 18 oz (500 g) are mostly insectivorous because they cannot tolerate the slow, complex digestive process of a herbivore. Larger animals, on the other hand, generate more heat and less of this heat is lost. They can therefore tolerate either a slower collection process (those that prey on larger vertebrates) or a slower digestive process (herbivores). Furthermore, mammals that weigh more than 18 oz (500 g) usually cannot collect enough insects during their waking hours to sustain themselves. The only large insectivorous mammals are those that feed on huge colonies of insects (ants or termites). By : Vivek Shukla and Ritesh 1/2/2014

30. 30 By : Vivek Shukla and Ritesh 1/2/2014

31. 31 Some examples are : 1 By : Vivek Shukla and Ritesh & 2 1/2/2014

34. Evolution 34 APES TO HUMAN 1&2 By : Vivek Shukla and Ritesh 1/2/2014

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